Acetaminophen Use During Pregnancy May Increase ADHD Risk: Study

New research suggests that the side effects of acetaminophen, the active ingredient in Tylenol and a number of other pain and cold medications, may increase the risk of attention-deficit/hyperactivity disorder (ADHD) when taken by pregnant women. 

In a study published in the October issue of the medical journal Pediatrics, Norwegian researchers report that there may be an association between acetaminophen use during pregnancy, and the risk of giving birth to a child who later develops ADHD.

However, some experts are saying that the study’s findings need to be approached cautiously, given the fever-reducing benefits of acetaminophen, and the belief that women should stay away from ibuprofen and some other analgesics due to even higher risks of pregnancy problems.

The study looked at data on nearly 113,000 children in the Norwegian Patient Registry, identified by the Norwegian Mother and Child Cohort Study. Researchers found that 2,246 of those children have been diagnosed with ADHD.

According to the findings, any use of acetaminophen during pregnancy resulted in a seven percent increased risk of ADHD in the first trimester, and a 27% increased risk during the third trimester. However, the study also found that using acetaminophen for more than 29 days during pregnancy more than doubled the risk of ADHD. The highest risk was for pregnant women, who used acetaminophen for 22 to 28 days for fever and infection, which was linked to a six-fold increased risk.

“Short-term maternal use of acetaminophen during pregnancy was negatively associated with ADHD in offspring,” the researchers concluded. “Long-term maternal use of acetaminophen during pregnancy was substantially associated with ADHD even after adjusting for indications of use, familial risk of ADHD, and other potential confounders.”

This is not the first study to warn that Tylenol and acetaminophen may have adverse health and developmental effects during pregnancy.

In July 2016, Spanish researchers came to similar conclusions as this most recent study, reporting that using acetaminophen during pregnancy doubled the risk of giving birth to a child with hyperactivity and impulsivity symptoms.

Another Norwegian study published in February 2016 found that exposure to Tylenol during pregnancy and shortly after birth could result in an increased risk of asthma.

Although most consumers assume that Tylenol is safe, acetaminophen products have been linked to a number of potential health risks. The pain killer has been identified as a leading cause for liver injury in the United States, causing an estimated 50,000 emergency room visits each year, including 25,000 hospitalizations and over 450 deaths annually. In addition, use of the medication has been linked to a risk of dangerous skin reactions, like Stephens-Johnson Syndrome.

In recent years, efforts have been ramped up to bring the risk of acetaminophen overdoses to the public’s attention and to reduce the amount of liver injury cases linked to the popular analgesic, which is also found in other pain killers and a number of cold medications.

In 2011, Johnson & Johnson lowered the maximum recommended dosage on Tylenol and other acetaminophen-based products from 4,000 mg per day to 3,000 mg per day. However, the drug maker now faces a number of Tylenol liver failure lawsuits, which involve allegations that important safety information from the public for decades.